There are many vehicles that utilize handlebars for control. Some examples of these vehicles are motorcycles including dirtbikes and three-wheeled versions, all terrain vehicles (ATVs), personal watercraft such as jetskis, snowmobiles and bicycles. All of these vehicles can provide a common problem: A significant vibration that is felt by a person through the handlebar.
The vibration is primarily caused by the constant engine vibration, although road and suspension inputs also contribute to a lesser degree. A similar problem exits in helicopter rotorheads, which also experience a constant vibratory input, and therefore must utilize a tuned mass damper
Vibrations cause involuntary muscle firing at the same frequently as the vibration input. A person's nervous system vibration reflex typically requires one vibration to “lock onto”. The one vibration would be the resonant frequency of the handlebar. The result is the person experiencing significant hand numbness and tingling. Unfortunately, for most people who routinely experience these effects, it is simply accepted as a result that can not be alleviated. Even when it becomes a dangerous effect, such as for professional motorcycle/dirtbike or bicycle riders, there is no solution to the problem. There have been attempts to provide some type of vibration damping, but most of these have not been very successful.
Obviously, there is a need to provide an effective means of vibration damping that can be easily implemented. By reducing or eliminating the level of harmonic resonance in handlebars, the effectiveness, comfort and duration of a person holding the handlebars is greatly increased.
A search of the prior art did not disclose literature or patents that read directly on the claims of the instant invention. However, the following U.S. patents are considered related.
Pat. No.INVENTORISSUED5,814,963Girard, et al29 Sep. 19986,009,986Bansemir, et al4 Jan. 20006,954,686B2Bourg, et al11 Oct. 2005
The U.S. Pat. No. 5,814,963 discloses a device for damping the vibrations of a structure subjected to dynamic stresses. The invention includes a main mass mounted on an elastic plate which is itself fitted into the structure whose vibrations are to be damped. The damping device additionally comprises at least one auxiliary mass that is connected to the main mass and is capable of being moved at least substantially parallel to the elastic plate as a function of the control pulses which are received from a computer.
The U.S. Pat. No. 6,009,986 discloses a mass damper for a dynamically excited part including a housing connected in a vibration-free manner with the part and a spring-mass system that can vibrate in the direction of the excitation of the part. The spring-mass system comprises a leaf-spring arrangement tensioned firmly to the housing on one side and provided on the other side at the free spring end with an inertial mass. Resonance adjustment is performed in a structurally simple and problem-free manner, solely by control interventions on the housing side and without mass shifts in the spring-mass system.
The U.S. Pat. No. 6,954,686 discloses a method of tuning a vibration absorber on a driving frequency, in which the absorber includes a damper block secured to a support having one end fixedly mounted in an orifice. The invention includes a measurement step for estimating the offset between the tuned frequency of the absorber and the driving frequency in order to produce a reference value; and an adjustment step of adjusting at least one adjustment value of the absorber to the reference value.
For background purposes and as indicative of the art to which the invention relates, reference may be made to the following remaining patents found in the search.
Pat. No.INVENTORISSUED3,767,181Van Der Burgt, et alOctober 19734,494,634KatoJanuary 19854,744,547HartelMay 19885,022,201Kobori, et alJune 19915,410,845Sakamoto, et alMay 19975,620,068Garnjost, et alApril 19975,906,254Schmidt, et alMay 19996,101,453Suwa, et alAugust 20006,427,815ZellerAugust 2002